Vibratory apparatus



Oct. 31, 1967 J ATTWQOD ET AL 3,350,582

VIBRATORY APPARATUS 2 Sheets-Sheet 1 Filed Jan. 13, 1965 JOEFZOU Oct. 31, 1967 ATTWOQD ET AL VIBRATORY APPARATUS 2 Shecs-Sheet 2 Filed Jan. 13, 1965 United States Patent 3,350,582 VIERATORY APPARATUS John G. Attwood, Oak Park, and Robert L. Kosrow, Elk Grove Village, 111., assignors to Union Special Machine Company, Chicago, 1th, a corporation of Illinois Filed Jan. 13, 1965, Ser. No. 425,133 16 Claims. (Cl. 310-8.1)

ABSTRACT OF THE DISCLOSURE An ultrasonic vibratory tool in which the transducer for the tool is provided with a supporting structure sepaar ate from that of the tool itself. A wire mesh pad element or a resilient electrically conductive adhesive is interposed between the transducer and its support to absorb the vibrations of the transducer and to provide a series of electrically conductive paths therebetween. An electrically conductive adhesive also is positioned between the transducer and the tool to enable the transmission of electrical as well as mechanical energy thereto.

This invention relates to vibratory apparatus and more particularly to apparatus for transmitting energy to an ultrasonic vibratory tool.

There has been developed a method and apparatus for bonding pieces of material through the use of ultrasonic techniques which is extremely rapid in action and highly efiicient. One such method-and apparatus is disclosed, for example, in the copending Attw-ood and Kosrow patent application Ser. No. 425,231 entitled Method and Apparatus for Forming Ultrasonic Seals filed concurrently herewith. In methods and apparatus of this type, there customarily is employed an ultrasonic vibratory tool having a natural mechanical resonant frequency. The tool is vibrated through the use of a crystal or other transducer which is electrically connected to a source of alternating current. The pieces of material to be joined are advanced between the vibrating tool and a stationary jaw, member to provide a uniform and continuous seam.

In vibratory apparatus of the foregoing type, the source of alternating current customarily is mounted in a stationary position. The transducer and the tool, on the other hand, vibrate rapidly at the frequency of the applied signal. It accordingly has been diificult to transmit electrical energy from the stationary current source to the rapidly moving transducer without excessive energy loss therebetween. In addition, difiiculties have been encountered in providing a positive mechanical bond between the transducer and the tool while at the same time facilitating the completion of the electrical circuit thereto.

Furthermore, the arrangements employed in prior vibratory apparatus for supporting the tool have proved deficient in several respects.

It is an object of this invention to provide new and improved apparatus for transmitting energy to an ultrasonic vibratory tool.

Another object of the invention is to provide such apparatus in which alternating current from a stationary source is readily supplied to a rapidly moving energy transducer.

3,350,582, Patented Oct. 31, 1967 A further object of the invention is to provide apparatus of the character indicated in which the mechanical oscillations of the transducer are transferred to the vibratory tool in a rapid and straightforward manner while at the same time insuring a positive electrical interconnection thereb'etween.

Still another object of the invention is to provide novel vibratory apparatus which is economical to manufacture and thoroughly reliable in operation.

In one illustrative embodiment of the invention, there is provided vibratory apparatus which includes an alternating current source of ultrasonic frequency and an energy transducer which is effective to convert alternating current from the source into periodic mechanical oscillations. The source is electrically connected to a support for the transducer, and the support and the transducer are interconnected in a unique manner to enable the eflicient transmission of electrical energy thereto. The oscillations of the transducer are transmitted to an ultrasonic vibratory tool to vibrate the tool at the desired frequency.

In accordance with one feature of the invention, a novel and advantageous arrangement is provided for transmitting electrical energy from the support to the transducer. In certain particularly good embodiments, this arrangement comprises a resilient wire mesh pad element of electrically conductive material which is interposed between the support and the transducer. In other advantageous embodiments, a layer of non-conductive adhesive is positioned between the support and the transducer and is treated with electrically conductive particles to enable the transmission of electrical energy therebetween. The arrangement is such that a plurality of electrically conductive paths is maintained between the support and the transducer at all times.

In accordance with another feature of the invention, in several good arrangements, the transducer and the vibratory tool are maintained in fixed relationship with each other through the use of an epoxy or other bonding means. Electrically conductive particles are substantially evenly distributed throughout the bonding means to transmit electrical energy from the transducer to the tool and thereby complete the electrical circuit thereto. With this arrangement, energy losses between the transducer and the tool are maintained at a minimum.

The present invention, as well as further objects and features thereof, will be understood more clearly and fully from the following description of certain preferred embodiments, when read with reference to the accompanying drawings, in which:

FIGURE 1 is an end elevational view of vibratory apparatus for ultrasonically bonding pieces of material in accordance with one illustrative embodiment of the invention, with certain parts shown in section and others omitted for purposes of clarity;

FIGURE 2 is an enlarged side elevational view, with certain parts shown broken away and in section, of a po r- 'tion of the apparatus illustrated in FIGURE 1, together with a schematic representation of an electrical circuit;

FIGURE 3 is an exploded perspective view of parts of the apparatus appearing in FIGURE 2;

FIGURE 4 is a horizontal sectional view taken along the line 4-4 in FIGURE 2; and

FIGURE 5 is an elevational view in general similar to a portion of FIGURE 2 but showing vibratory apparatus in accordance with another illustrative embodiment of the invention.

Referring to FIGURE 1 of the drawings, there is shown an ultrasonic vibratory apparatus for interconnecting pieces of thermoplastic sheet material, for example, which includes a vibratory tool of electrically conductive material and an opposed jaw 11. The tool 10 and jaw 11 are spaced apart in vertical alignment with each other to form a gap therebetween. The tool comprises an elongated exponential horn which is arranged for vibratory motion in a longitudinal mode. The horn is of tapered, generally conical figuration but is flared at its smaller upper end to provide a substantially flat horizontal surface 12 in facing relationship with an adjacent surface 13 of the jaw 11. In certain advantageous embodiments, there is provided a series of small protrusions (not visible in FIGURE 1) on the facing surfaces 12 and 13 to enable the formation of an ultrasonic bond in preselected local areas therebetween.

The horn 10 is dimensioned to vibrate at a natural mechanical resonant frequency which is above the upper range of the audible spectrum and illustratively lies between twenty thousand cycles per second and several hundred thousand cycles per second or even higher. The reflection of a portion of the vibrations from the boundaries of the horn produces standing wave patterns which include one or more zones or nodes of minimum motion at one-half wavelength intervals and other zones or antinodes of maximum motion at distances of one-quarter wavelength from an adjacent node. The longitudinal dimension of the horn is such that the smaller upper end terminates at an antinode to provide vibrations of maximum amplitude. This antinode is spaced one-quarter wavelength above a node intermediate the horns ends which exhibits little or no vibratory motion.

The ultrasonic horn It) is supported at the node by a support unit indicated generally at 15. As best shown in FIGURE 4, the support unit 15 includes an electrically conductive horizontal plate 16 of generally annular configuration which is provided with three inwardly extending pointed screws 17. These screws are arranged to bite into the side of the horn at the node and thereby provide a rigid support therefor without substantial affect on the horns vibratory movement. Three integrally formed flanges 18 extend outwardly from the plate 16 and include grommets 19 (FIGURES 1 and 2) of rubber or other non-conductive material adjacent their outer ends. The grommets 19 accommodate corresponding bolts 20 which connect the plate 16 to a generally rectangular support plate 21. This latter plate is arranged parallel to and immediately beneath the plate 16 and is provided with an enlarged centrally located aperture through which the horn extends.

The plate 21 is supported at its corners intermediate the ends of four upstanding legs 22. The legs 22 are secured to a base member 24 and are provided with side panels 25 to substantially enclose the horn 10. A horizontal table 26 is mounted on the upper ends of the legs 22. The horn )10 extends through a suitable opening in the table 26 with the horizontal surface 12 flush with the upper surface of the table. The table serves as a support for the pieces of material to be joined.

Extending downwardly from the support plate 21 are electrically conductive legs 28. These legs are affixed by screws 29 to a generally cup-shaped member 30 which forms a portion of the support unit 15 and is fabricated from rubber or other dielectric material. As best shown in FIGURES 2 and 3, a flat brass disk 32 is carried within the support member 30. and this disk includes an integrally formed tab 33 which is electrically connected to a jack 34 mounted on the outer cylindrical surface of the 'member 30. A second jack 35 is affixed to an upwardly protruding portion 36 of the member 30. The jack 35 is connected to the horizontal plate 16 by an insulated conductor 37.

Resting on the brass disk 32 within the cup-shaped member 30 is a resilient wire mesh 40. The wire mesh 40 is of cylindrical configuration and includes a series of closely spaced fine wires of electrically conductive material which provide a large number of conductive paths through the mesh and give it its resilient characteristics. The mesh is in the form of a comparatively thick pad having its lower surface in facing contact with the upper surface of the disk 32.

A disk-shaped transducer element 42 is positioned in juxtaposition with the opposite, upper surface of the wire mesh 40. The mesh 40 is compressed slightly between the transducer 42 and the disk 32 and serves to resiliently maintain these components in spaced-apart relationship with each other. As will be understood, the transducer is effective to convert an alternating current signal applied thereto into periodic mechanical oscillations at the frequency of the applied signal. Although in some embodiments of the invention magnetostrictive-type transducers are employed with good effect, in the illustrated embodiments the transducer 42 advantageously comprises a piezoelectric crystal which is provided with a coating 43 of silver or other electrically conductive material.

The upper face of the crystal 42 and the enlarged lower face of the ultrasonic tool 10 are bonded together by a non-conductive adhesive layer 45 which preferably comprises epoxy resin. The epoxy resin generally includes a base resin which is combined with a suitable hardener and inert mineral fillers. For a more detailed discussion of representative resins useful in connection with the invention, reference may be had, for example, to the article entitled Resins for Adhesives by R. F. Blomquist at pp. l77-188 of Modern Plastics, September 1958, vol. 36, No. 1A.

The epoxy layer 45 includes a series of comparatively hard granular particles 46 which substantially evenly distributed throughout the epoxy. The particles 46 are of silver or other electrically conductive material and are closely spaced to one another such that they provide a series of electrically conductive paths from the transducer 42 to the ultrasonic tool 10, for purposes that will become more fully apparent hereinafter.

The apparatus is controlled through the use of electrical circuitry shown schematically in FIGURE 2. This circuitry comprises a source of alternating current included within a control circuit 48 which is electrically connected to a treadle-operated switch 50. The circuit 48 is arranged to produce an alternating current signal of predetermined ultrasonic frequency which is amplified by an amplifier 51. As more fully described in the copending Attwood and Kosrow patent application Ser. No. 425,240 entitled Control Circuit for Electro-Mechanical Devices filed concurrently herewith, the amplified alternating current signal appears across two output terminals 52 and 53 of the circuit 48 as an ultrasonic signal of closely controlled frequency. The output terminal 52 is electrically connected to the jack 34 by a conductor 54, while the output terminal 53 is similarly connected to the jack 35 by a conductor 55.

The jaw 11 (FIGURE 1) comprises an anvil which is arranged in spaced juxtaposition with the horizontal surface 12 of the tool 10. The jaw is adjustably mounted on a bracket assembly indicated generally at 57 which is carried by a standard 58 extending upwardly from the base 24. The bracket assembly 57 includes a laterally extending arm 60 which is secured to the standard by locking members 61. Upon the loosening of the members 61, the arm 60 is movable either upwardly or downwardly to produce corresponding movements of the jaw.

A vertically reciprocable rack 62 is carried in a cooperating track (not visible in FIGURE 1) adjacent the inwardly extending portion of the arm 60. The rack 62 meshes with a pinion connected to a knurled knob 63 to.

enable manual movement of the rack 62 in a vertical direction with respect to the arm 60. During the seaming operation, this movement is prevented by wing screws 64 which clamp the rack 62 to the arm 60. A flat horizontal plate 65 is secured to the upper end of the rack 62 and is provided with an adjustable stop member 66 which extends therefrom to a position adjacent the upper surface of the arm 60. The member 66 serves to limit downward movement of the rack with respect to the arm. The rack is biased in a downward direction relative to the arm by an elongated coil spring 67. The lower end of this spring bears against the upper horizontal surface of the arm, while its upper end is connected to the lower surface of the plate 65. Upon the loosening of the wing screws 64, the spring 67 draws the rack downwardly from its uppermost position (the position shown) until the member 66 engages the arm.

The rack 62 supports a generally C-shaped head 68. The arms 69 and 70 of the head 68 extend horizontally above the vibratory tool and are provided with aligned apertures 71 and 72. These apertures accommodate a vertically reciprocable rod 73 which is connected to the jaw 11 at its lower end. A collar 74 is secured to the rod 73 intermediate the arms 69' and 70, and this collar supports the lower end of a comparatively strong coil spring 75. The spring 75 is disposed around the rod 73, and its upper end affixed to the lower surface of the arm 69 to bias the rod and its attached jaw in a downward direction. The arrangement is such that, with the spring 75 in its fully expanded position, the lower face 13 of the jaw is maintained in spaced relationship with the horizontal surface 12 on the tool 10.

The temperature of the vibratory tool 10 is controlled at predetermined points during the seaming operation by a blower unit indicated generally at 76. The blower unit 76 is supported by a bracket 77 afiixed to the standard 58 and includes a cylindrical discharge conduit 78 which extends horizontally through a suitable opening in one of .the side panels 25. As more fully described in the aforementioned Attwood and Kosrow patent application entitled Method and Apparatus for Forming Ultrasonic Seals, the discharge end of the conduit 78 is positioned in close juxtaposition with the tool 10 and is effective to direct a stream of air at controlled temperatures across the tool both during and prior to the formation of the seam. The side panel 25 on the side of the tool opposite that adjacent the conduit 78 is provided with a series of apertures 79 to insure the free circulation of air across the tool.

In operation the apparatus is initially adjusted to establish an appropriate gap between the vibratory tool 10 and the jaw 11. This gap depends for the most part on the thicknesses of the pieces of material to be bonded together. A coarse adjustment of the gap is effected by loosening the locking members 61 and sliding the arm 60 upwardly or downwardly with respect to the standard 58. To provide a precise adjustment of the jaw 11 with respect to the tool 10, the wing screws 64 are loosened, and the knurled knob 63 is rotated to move the rack and the jaw in a vertical direction with respect to the tool to establish the gap. The threaded stop member 66 is then adjusted to prevent the jaw from approaching the tool closer than the desired jaw setting. v

Upon the operation of the foot treadle 50 (FIGURE 2), the control circuit 48 produces an alternating current signal of predetermined ultrasonic frequency at the output terminals 52 and 53. This frequency corresponds to the resonant frequency of the tool 10. The current from the control circuit follows a path from the output terminal 52, the conductor 54 and the jack 34 to the electrically conductive disk 32. As indicated heretofore, the wire mesh pad element 40 is compressed slightly between the upper face of the disk 32 and the lower face of the transducer 42. The mesh 40 maintains the transducer and the disk in spaced-apart relationship with the individual wires at the respective lower and upper surfaces of the mesh pressed against the upper face of the disk and the lower face of the transducer. The :mesh thus provides a series of electrically conductive paths between the transducer and the disk at all times to insure an electrically good connection therebetween irrespective of the transducer frequency.

The current path continues from the transducer element 42 to the vibratory tool 10 through the adhesive layer 45. The silver granules 46 in the layer 45 define a plurality of current conducting paths between the transducer and the tool which greatly facilitate the transmission of electrical energy thereto without substantial energy loss. The circuit is completed from the tool 19 through the pointed screws 17, the annular plate 16, the conductor 37, the jack 35 and the conductor 55 leading to the output terminal 53 of the control circuit 48.

The current applied to the transducer 42 is converted into periodic mechanical oscillations of a frequency corresponding to that of the alternating current signal. The resulting mechanical energy is transmitted through the adhesive layer 45 to the tool 10 to vibrate the upper end of the tool at its natural resonant frequency but at substantially increased amplitude. The vibratory energy of the tool is applied to the pieces of material being advanced along the table 26 between the tool and the jaw 11 to form a smooth and uniform seam. Both before and during the formation of the seam, the blower unit 76 is effective to provide precise control over the temperature of the tool and thereby further stabilize its operating frequency.

As the upper end of the tool 10 vibrates, the resistance to movement of the coil spring 75 sufiicient to hold the jaw 11 in a stationary position. However, in cases in which the amplitude of this end of the tool inadvertently is increased above its design amplitude, or when the gap between the tool and the jaw has been set incorrectly, for example, the spring 75 permits limited upward movement of the jaw. With this arrangement, the possibility of substantial wear or other damage to the apparatus is reduced.

As indicated heretofore, in the embodiment of FIG- URES l-4 the vibratory tool 10 comprises a generally conical horn of the exponential type. In other advantageous arrangements, horns of a non-exponential character are employed, again with good results. For example, in FIGURE 5 there is shown a vibratory tool which includes two oppositely disposed inwardly tapering fiat surfaces 86 and 87 adjacent the lower portion of the tool. The upper tool portion forms an extension 88 of the lower portion and is of elongated, generally rectangular cross-section. Upon the application of vibratory energy to the tool 85, the upper end of the tool oscillates in its longitudinal mode at increased amplitude in a manner generally similar to that described above.

In the FIGURE 5 embodiment, the current paths from the support unit to the transducer are provided through the use of electrically conductive particles which are distributed throughout a layer of adhesive, rather than by the wire mesh pad element 40' (FIGURES 2 and 3). The conductor 54 from the alternating current source is connected to an electrically conductive support plate 50 for the crystal 42. This plate is bonded to the lower surface of the crystal by an epoxy layer 91 which serves to maintain the plate and the crystal in spaced-apart relationship with each other. A series of silver granules 92 are substantially evenly distributed throughout the layer 91 and are arranged in close proximity with each other to provide a plurality of electrically conductive paths between the plate and the crystal.

The alternating current from the source flows along the conductor 54 to the plate 50 and then through the paths established by the granules 92 to the transducer 42. The circuit is then completed through the tool 85 and the remaining portions of the support unit in a manner 7 similar to that described above. The use of the adhesive layer '91 and the granules 92 between the plate 90 and the transducer 42 performs the combined functions of establishing a good electrical connection between the plate 90 and the transducer 42 and also of providing an adhesive bond therebetween.

The terms and expressions which have been employed are used as ten-ms of description and not of limitation, and there is no intention in the use of such terms and expressions of including any equivalents of the features shown or described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

1. Vibratory apparatus comprising an alternatin current source of ultrasonic frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an ultrasonic vibratory tool operatively associated with said transducer means, means for transmitting energy from said transducer means to said ultrasonic vibratory tool, a support for said transducer means electrically connected to said source, and means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, to thereby transmit said alternating current to said transducer means.

2. Vibratory apparatus comprising an alternating current source of ultrasonic frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated vibratory tool, bonding means interconnecting said transducer means and one end of vibratory tool for transmitting electrical and mechanical energy therebetween, a support for said transducer means electrically connected to said source, and means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, to thereby transmit said alternating current to said transducer means.

3. Vibratory apparatus comprising an alternating current source of ultrasonic frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means for interconnecting said transducer means and one end of said ultrasonic vibratory tool for transmitting energy therebetween, a support for said transducer means electrically connected to said source, and resilient means including an electrically conductive pad element interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, to thereby transmit said alternatnig current to said transducer means.

4. Vibratory apparatus comprising an alternating current source of ultrasonic frequency, transducer means for converting alternatin current from said source into periodic mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means for adhesively interconnecting said transducer means and one end of said ultrasonic vibratory tool for transmitting electrical energy therebetween, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, a support for said transducer means electrically connected to said source, and resilient means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, said resilient means including a compressible wire mesh pad element of conductive material having one face in abutting relationship and substantially coextensive with said transducer means and the other face resting against said support, to thereby transmit said alternating current to said transducer means.

5. Vibratory apparatus comprising an alternating current source of ultrasonic frequency, transducer means for converting alternating current from said source into perioric mechanical oscillations, an elongated ultrasonic vibratory tool, first bonding means for interconnecting said transducer means and one end of said ultrasonic vibratory tool for transmitting electrical energy therebetween, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, a support for said transducer means electrically connected to said source, and second bonding means interposed between said transducer means and said support for adhesively maintaining the same in spaced-apart relationship with each other, said second bonding means including a plurality of electrically conductive granular particles substantially evenly distributed throughout said second bonding means for providing a series of electrically conductive paths between said transducer means and said support, to thereby transmit said alternating current to said transducer means.

6. Vibratory apparatus comprising an alternating current source of predetermined frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated vibratory tool, bonding means for adhesively interconnecting said transducer means and one end of said vibratory tool and for transmitting energy from said transducer means to said tool, to vibrate said tool in response to said periodic mechanical oscillations but an increased amplitude, support means including a first portion for supporting said tool at a point of minimum vibration and a second portion electrically connected to said source for supporting said transducer means, and means interposed between said tranducer means and said second portion for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, to thereby transmit said alternating current to said transducer means.

7. Vibratory apparatus comprising an alternating current source of predetermined frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated vibratory tool, bonding means for interconnecting said vibratory tool and said transducer means, a series of comparatively hard granular particles substantially evenly distributed throughout said bOnding means for transmitting electrical energy from said transducer means to said vibratory tool, a support for said transducer means electrically connected to said source, and means interposed between said transducer means and said support for electrically interconnecting the same, to thereby transmit said alternating current to said transducer means.

8. Vibratory apparatus comprising an alternating current source of ultrasonic frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means of dielectric material for adhesively interconnecting said transducer means and one end of said ultrasonic vibratory tool, a series of electrically conductive granular particles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said ultrasonic vibratory tool, a support for said transducer means electrically connected to said source, and conductive means interposed between said transducer means and said support for maintaining the same in predetermined relationship with each other, to thereby provide an electrical path which extends from said source,

then to said support, then to said conductive means, then to said transducer means and then along the granular particles in said bonding means to said vibratory tool.

9. Vibratory apparatus comprising an alternating current source of predetermined frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated vibratory tool, bonding means of dielectric material for adhesively interconnecting said transducer means and one end of said vibratory tool, a series of electrically conductive granular particles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said vibratory tool, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, a support for said transducer means electrically connected to said source, and conductive means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, to thereby complete an electrical circuit which extends from said source, then to said support, then along said paths to said transducer means and then through the granular particles in said bonding means to said vibratory tool.

10. Vibratory apparatus comprising an alternating current source of predetermined frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated vibratory tool, bonding means of dielectric material for adhesively interconnecting said transducer means and one end of said vibratory tool, a series of electrically conductive comparatively hard granular particles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said vibratory tool, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, a support for said transducer means electrically connected to said source, and resilient conductive means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, said resilient means including a compressible Wire mesh pad element of conductive material having one face in abutting rela tionship with said transducer means and the other face resting against said support, to thereby complete an electrical circuit which extends from said source, then to said support, then along said paths to said transducer means and then through the granular particles in said bonding means to said vibratory tool.

11. Vibratory apparatus comprising an alternating current source of predetermined ultrasonic frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means of dielectric material for adhesively interconnecting said transducer means and one end of said ultrasonic vibratory tool, a series of electrically conductive granular patricles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said ultrasonic vibratory tool, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, support means including a first portion for supporting said tool at a point of minimum vibration and a second portion electrically connected to said source for supporting said transducer means, and resilient conductive means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, said resilient means including a compressible wire mesh pad element of conductive material having one face in abutting relationship with said transducer means and the other face resting against said support, to thereby complete an electrical circuit which extends from said source, then to said support, then along said paths 1.0 to said transducer means and then through the granular particles in said bonding means to said vibratory tool.

12. Vibratory apparatus comprising an alternating current source of predetermined ultrasonic frequency, transducer means including a piezoelectric crystal for converting mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means of dielectric material for adhesively interconnecting said crystal and one end of said ultrasonic vibratory tool, a series of electrically conductive granular particles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said ultrasonic vibratory tool, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, a support for said transducer means electrically connected to said source, and resilient conductive means interposed between said trans-ducer means and said support for maintaining the same in spacedapart relationship with each other and for providing a series of electrically conductive paths therebetween, said resilient means including a compressible wire mesh pad element of conductive material having one face in abutting relationship and substantially coextensive with said transducer means and the other face resting against said support, to thereby complete an electrical circuit which extends from said source, then to said support, then along said paths to said transducer means and then through the granular particles in said bonding means to said vibratory tool.

13. Vibratory apparatus of the character set forth in claim 12 in which said piezoelectric crystal is of diskshaped configuration and is provided with a coating thereon of electrically conductive material.

14. Vibratory apparatus comprising an alternating current source of predetermined ultrasonic frequency, transducer means including a disk-shaped piezoelectric crystal for converting alternating current from said source into periodic mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means of dielectric material for adhesively interconnecting one face of said crystal and an end of said ultrasonic vibratory tool, a series of electrically conductive granular particles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said ultrasonic vibratory tool, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, said tool having at least one zone of minimum vibration and other zones of maximum vibration, a support for said vibrating tool and said transducer means electrically connected to said source, said support including a first portion for supporting said tool at a plurality of discrete points adjacent said zone of minimum vibration and a second portion carried by said first portion for supporting said transducer means, and resilient conductive means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, said resilient means including a compressible wire mesh pad element of conductive material having one face in abutting relationship with said transducer means and the other face resting against said support, to thereby complete an electrical circuit which extends from said source, then to said support, then along said paths to said transducer means and then through the granular particles in said bonding means to said vibratory tool.

15. Vibratory apparatus comprising an alternating current source of predetermined ultrasonic frequency, transducer means for converting alternating current from said source into periodic mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means of dielectric material for adhesively interconnecting said transducer means and one end of said ultrasonic vibratory tool, a first series of electrically conductive granular particles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said ultrasonic vibratory tool, a support for said transducer means electrically connected to said source, and conductive means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, said conductive means comprising a second series of electrically conductive granular particles substantially evenly distributed throughout the space between said transducer means and said support, to thereby complete an electrical circuit which extends from said source, then to said support, then along said paths to said transducer means and then through the granular particles in said bonding means to said vibratory tool.

16. Vibratory apparatus comprising an alternating current source of predetermined ultrasonic frequency, transducer means including a disk-shaped piezoelectric crystal for converting alternating current from said source into periodic mechanical oscillations, an elongated ultrasonic vibratory tool, bonding means of dielectric material for adhesively interconnecting one face of said crystal and an end of said ultrasonic vibratory tool, a first series of electrically conductive granular particles substantially evenly distributed throughout said bonding means for transmitting electrical energy from said transducer means to said ultrasonic vibratory tool, to vibrate said tool in response to said periodic mechanical oscillations but at increased amplitude, said tool having at least one zone of minimum vibration and other zones of maximum for said vibratory tool and said transducer means electricalvibration, a support 3 ly connected to said source, said support'includ'ing 'a first portion for supporting said tool at a plurality of discrete points adjacent said zone of minimum vibration and a second portion carried by said first portion for supporting said transducer means, and conductive means interposed between said transducer means and said support for maintaining the same in spaced-apart relationship with each other and for providing a series of electrically conductive paths therebetween, said conductive means comprising a second series of electrically conductive granular particles substantially evenly distributed through-out the space between said transducer means and said support, to thereby complete an electrical circuit which extends from said source, then to said support, then along said paths to said trans-ducer means and then through the granular particles in said bonding means to said vibratory tool.

References Cited UNITED STATES PATENTS 2,150,328 3/1939 Keall 3108.9 2,702,692 2/1955 Kessler 259--1 2,731,573 1/1956 Hansen 15673 2,946,904 7/1960 Renaut 310-8.2 2,991,594 7/1961 Brown 310-26 3,072,777 1/1963 McKechnie 3l08;1 3,103,310 9/1963 Lang 259-1 3,184,353 5/1965 Balarnuth 15673 MILTON O. HIRSHFIELD, Primary Examiner.

J. D. MILLER, Assistant Examiners 

1. VIBRATORY APPARATUS COMPRISING AN ALTERNATING CURRENT SOURCE OF ULTRASONIC FREQUENCY, TRANSDUCER MEANS FOR CONVERTIG ALTERNATING CURRENT FROM SAID SOURCE INTO PERIODIC MECHNICAL OSCILLATIONS, AN ULTRASONIC VIBRATORY TOOL OPERTIVELY ASSOCIATED WITH SAID TRANSDUCER MEANS, MEANS FOR TRANSMITTING ENERGY FROM SAID TRANSDUCER MEANS TO SAID ULTRANSONIC VIBRATORY TOOL, A SUPPORT FOR SAID TRANSDUCER MEANS ELECTRICALLY CONNECTED TO SAID SOURCE, AND MEANS INTERPOSED BETWEEN SAID TRANSDUCER MEANS AND SAID SUPPORT FOR MAINTAINING THE SAME IN SPACED-APART RELATIONSHIP WITH EACH OTHER AND FOR PROVIDING A SERIES OF 